public static void Main(string[] args) { // Runs several concurrent threads that access an item that periodically expires and is re-created. MemoryCache cache = new MemoryCache(new MemoryCacheOptions()); string key = "MyKey"; var options = new MemoryCacheEntryOptions().SetAbsoluteExpiration(TimeSpan.FromMilliseconds(50)); var tasks = new List<Task>(); for (int threads = 0; threads < 100; threads++) { var task = Task.Run(() => { for (int i = 0; i < 110000; i++) { object value; if(!cache.TryGetValue(key, out value)) { // Fake expensive object creation. for (int j = 0; j < 1000000; j++) { } cache.Set(key, new object(), options); } } }); tasks.Add(task); } Console.WriteLine("Running"); Task.WaitAll(tasks.ToArray()); Console.WriteLine("Done"); }
public void Main() { IMemoryCache cache = new MemoryCache(new MemoryCacheOptions()); object result; string key = "Key"; object newObject = new object(); object state = new object(); // Basic CRUD operations: // Create / Overwrite result = cache.Set(key, newObject); result = cache.Set(key, new object()); // Retrieve, null if not found result = cache.Get(key); // Retrieve bool found = cache.TryGetValue(key, out result); // Delete cache.Remove(key); // Cache entry configuration: // Stays in the cache as long as possible result = cache.Set( key, new object(), new MemoryCacheEntryOptions().SetPriority(CacheItemPriority.NeverRemove)); // Automatically remove if not accessed in the given time result = cache.Set( key, new object(), new MemoryCacheEntryOptions().SetSlidingExpiration(TimeSpan.FromMinutes(5))); // Automatically remove at a certain time result = cache.Set( key, new object(), new MemoryCacheEntryOptions().SetAbsoluteExpiration(DateTimeOffset.UtcNow.AddDays(2))); // Automatically remove at a certain time, which is relative to UTC now result = cache.Set( key, new object(), new MemoryCacheEntryOptions().SetAbsoluteExpiration(relative: TimeSpan.FromMinutes(10))); // Automatically remove if not accessed in the given time // Automatically remove at a certain time (if it lives that long) result = cache.Set( key, new object(), new MemoryCacheEntryOptions() .SetSlidingExpiration(TimeSpan.FromMinutes(5)) .SetAbsoluteExpiration(DateTimeOffset.UtcNow.AddDays(2))); // Callback when evicted var options = new MemoryCacheEntryOptions() .RegisterPostEvictionCallback( (echoKey, value, reason, substate) => { Console.WriteLine(echoKey + ": '" + value + "' was evicted due to " + reason); }); result = cache.Set(key, new object(), options); // Remove on token expiration var cts = new CancellationTokenSource(); options = new MemoryCacheEntryOptions() .AddExpirationToken(new CancellationChangeToken(cts.Token)) .RegisterPostEvictionCallback( (echoKey, value, reason, substate) => { Console.WriteLine(echoKey + ": '" + value + "' was evicted due to " + reason); }); result = cache.Set(key, new object(), options); // Fire the token to see the registered callback being invoked cts.Cancel(); // Expire an entry if the dependent entry expires using (var link = cache.CreateLinkingScope()) { cts = new CancellationTokenSource(); cache.Set("key1", "value1", new MemoryCacheEntryOptions() .AddExpirationToken(new CancellationChangeToken(cts.Token))); // expire this entry if the entry with key "key1" expires. cache.Set("key2", "value2", new MemoryCacheEntryOptions() .AddEntryLink(link) .RegisterPostEvictionCallback( (echoKey, value, reason, substate) => { Console.WriteLine(echoKey + ": '" + value + "' was evicted due to " + reason); })); } // Fire the token to see the registered callback being invoked cts.Cancel(); }
public async Task ProcessAsync_FlowsEntryLinkThatAllowsAddingTriggersToAddedEntry() { // Arrange var id = "some-id"; var expectedContent = new DefaultTagHelperContent(); expectedContent.SetContent("some-content"); var tokenSource = new CancellationTokenSource(); var cache = new MemoryCache(new MemoryCacheOptions()); var cacheEntryOptions = new MemoryCacheEntryOptions() .AddExpirationTrigger(new CancellationTokenTrigger(tokenSource.Token)); var tagHelperContext = new TagHelperContext( allAttributes: new TagHelperAttributeList(), items: new Dictionary<object, object>(), uniqueId: id, getChildContentAsync: () => { TagHelperContent tagHelperContent; if(!cache.TryGetValue("key1", out tagHelperContent)) { tagHelperContent = expectedContent; cache.Set("key1", tagHelperContent, cacheEntryOptions); } return Task.FromResult(tagHelperContent); }); var tagHelperOutput = new TagHelperOutput("cache", new TagHelperAttributeList { { "attr", "value" } }); tagHelperOutput.PreContent.SetContent("<cache>"); tagHelperOutput.PostContent.SetContent("</cache>"); var cacheTagHelper = new CacheTagHelper(cache) { ViewContext = GetViewContext(), }; var key = cacheTagHelper.GenerateKey(tagHelperContext); // Act - 1 await cacheTagHelper.ProcessAsync(tagHelperContext, tagHelperOutput); TagHelperContent cachedValue; var result = cache.TryGetValue(key, out cachedValue); // Assert - 1 Assert.Equal(expectedContent.GetContent(), tagHelperOutput.Content.GetContent()); Assert.True(result); Assert.Equal(expectedContent, cachedValue); // Act - 2 tokenSource.Cancel(); result = cache.TryGetValue(key, out cachedValue); // Assert - 2 Assert.False(result); Assert.Null(cachedValue); }
public void Main() { IMemoryCache cache = new MemoryCache(new MemoryCacheOptions()); object result; string key = "Key"; object newObject = new object(); object state = new object(); // Basic CRUD operations: // Create / Overwrite result = cache.Set(key, newObject); result = cache.Set(key, context => new object()); result = cache.Set(key, state, context => new object()); // Retrieve, null if not found result = cache.Get(key); // Retrieve bool found = cache.TryGetValue(key, out result); // Delete cache.Remove(key); // Conditional operations: // Retrieve / Create when we want to lazily create the object. result = cache.GetOrSet(key, context => new object()); // Retrieve / Create when we want to lazily create the object. result = cache.GetOrSet(key, state, context => new object()); // Cache entry configuration: // Stays in the cache as long as possible result = cache.GetOrSet(key, state, context => { context.SetPriority(CachePreservationPriority.NeverRemove); return new object(); }); // Automatically remove if not accessed in the given time result = cache.GetOrSet(key, state, context => { context.SetSlidingExpiration(TimeSpan.FromMinutes(5)); return new object(); }); // Automatically remove at a certain time result = cache.GetOrSet(key, state, context => { context.SetAbsoluteExpiration(new DateTime(2014, 12, 31)); // or relative: // context.SetAbsoluteExpiration(TimeSpan.FromMinutes(5)); return new object(); }); // Automatically remove if not accessed in the given time // Automatically remove at a certain time (if it lives that long) result = cache.GetOrSet(key, state, context => { context.SetSlidingExpiration(TimeSpan.FromMinutes(5)); context.SetAbsoluteExpiration(new DateTime(2014, 12, 31)); // or relative: // context.SetAbsoluteExpiration(TimeSpan.FromMinutes(5)); return new object(); }); // Callback when evicted result = cache.GetOrSet(key, state, context => { context.RegisterPostEvictionCallback((echoKey, value, reason, substate) => Console.WriteLine(echoKey + ": '" + value + "' was evicted due to " + reason), state: null); return new object(); }); // Remove on trigger var cts = new CancellationTokenSource(); result = cache.GetOrSet(key, state, context => { context.AddExpirationTrigger(new CancellationTokenTrigger(cts.Token)); return new object(); }); result = cache.GetOrSet(key, context => { var link = new EntryLink(); var inner1 = cache.GetOrSet("subkey1", link, subContext => { return "SubValue1"; }); string inner2; using (link.FlowContext()) { inner2 = cache.GetOrSet("subkey2", subContext => { return "SubValue2"; }); } context.AddEntryLink(link); return inner1 + inner2; }); }